$ git clone -n https://src.fedoraproject.org/rpms/squid.git /var/lib/mock/f42-build-side-1-3585943-46912/root/chroot_tmpdir/scmroot/squid
Cloning into '/var/lib/mock/f42-build-side-1-3585943-46912/root/chroot_tmpdir/scmroot/squid'...
$ git fetch origin 9c651e4fe8d7da27226525e8fc3c7c84f7d724bf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/squid
 * [new ref]         9c651e4fe8d7da27226525e8fc3c7c84f7d724bf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9c651e4 new version 6.13